Spelling Correction for Winforms Textboxes

A simple “one component per form” (or other container) solution for multi-lingual spell checking and correction in Windows Forms applications.

Spell checking for your existing Winforms applications without replacing any textboxes

A .NET spelling highlighting and correction control specifically for Winforms textboxes that runs natively on all .NET frameworks from 3.5 upwards as well as .NET5 and .NET6. The controls integrates with existing Winforms textboxes, which means that replacing your existing textboxes is not required.

Multi-Lingual Spell Checking

The control is multi-lingual, providing spell checking in any language. It utilizes the in-built spelling capabilities  of  Windows 8, 8.1, 10, and Windows 11 and because of this spell checking is limited only by the Windows language packs end-users have installed on their PC's. Unless specified otherwise spell checking will always be performed in the end-users default language.


  • Multi-lingual (works with all Windows 8, 8.1, 10 and Windows 11 language packs)
  • Inline spelling error highlighting in any language
  • Spelling correction via context menu and spelling suggestions dialog
  • Works with single line and multi-line textboxes
  • Custom dictionaries
  • Run natively on Windows 8, 8.1, 10, and 11
  • Does not require dictionary files
  • Integrates with existing Winforms textboxes (no need to replace any controls)

Simple to implement

Place the control on a windows form or other container object, such as a frame. Then set the language to perform spell checking and correction in (defaults to the system default language), initiate the spelling by calling InitSpelling_AllTextboxes() to hook all your textboxes.

Textboxes may also be excluded individually if there are any that don't require spell checking.

Minimum Requirements

  • Winforms application running under .NET framework 3.5 or greater or .NET5 / .NET6
  • Windows 8, Windows 8.1, Windows 10, or Windows 11 (Windows 7 is not supported)
  • Please note: The DLL may be used in applications running on Windows 7 and  XP applications but spell checking will not be performed